UNASSIGNED: Precise estimation of a patient\'s drug metabolism capacity is important for antiseizure dose personalization.
UNASSIGNED: To quantify the differences in plasma concentrations for antiseizure drugs associated with variants of genes encoding drug metabolizing enzymes.
UNASSIGNED: PubMed, Clinicaltrialsregister.eu, ClinicalTrials.gov, International Clinical Trials Registry Platform, and CENTRAL databases were screened for studies from January 1, 1990, to September 30, 2023, without language restrictions.
UNASSIGNED: Two reviewers performed independent study screening and assessed the following inclusion criteria: appropriate genotyping was performed, genotype-based categorization into subgroups was possible, and each subgroup contained at least 3 participants.
UNASSIGNED: The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed for data extraction and subsequent quality, validity, and risk-of-bias assessments. The results from the included studies were pooled with random-effect meta-analysis.
UNASSIGNED: Plasma concentrations of antiseizure drugs were quantified with the dose-normalized area under the concentration-time curve, the dose-normalized steady state concentration, or the concentrations after a single dose at standardized dose and sampling time. The ratio of the means was calculated by dividing the mean drug plasma concentrations of carriers and noncarriers of the pharmacogenetic variant.
UNASSIGNED: Data from 98 studies involving 12 543 adult participants treated with phenytoin, valproate, lamotrigine, or carbamazepine were analyzed. Studies were mainly conducted within East Asian (69 studies) or White or European (15 studies) cohorts. Significant increases of plasma concentrations compared with the reference subgroup were observed for phenytoin, by 46% (95% CI, 33%-61%) in CYP2C9 intermediate metabolizers, 20% (95% CI, 17%-30%) in CYP2C19 intermediate metabolizers, and 39% (95% CI, 24%-56%) in CYP2C19 poor metabolizers; for valproate, by 12% (95% CI, 4%-20%) in CYP2C9 intermediate metabolizers, 12% (95% CI, 2%-24%) in CYP2C19 intermediate metabolizers, and 20% (95% CI, 2%-41%) in CYP2C19 poor metabolizers; and for carbamazepine, by 12% (95% CI, 3%-22%) in CYP3A5 poor metabolizers.
UNASSIGNED: This systematic review and meta-analysis found that CYP2C9 and CYP2C19 genotypes encoding low enzymatic capacity were associated with a clinically relevant increase in phenytoin plasma concentrations, several pharmacogenetic variants were associated with statistically significant but only marginally clinically relevant changes in valproate and carbamazepine plasma concentrations, and numerous pharmacogenetic variants were not associated with statistically significant differences in plasma concentrations of antiseizure drugs.

BACKGROUND: Status epilepticus (SE) is potentially life-threatening, however, it is unclear which antiepileptic drugs (AEDs) should be used as second-line AEDs.
OBJECTIVE: We conducted a network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing multiple second-line AEDs for SE to investigate the efficacy of AEDs.
METHODS: We searched MEDLINE, CENTRAL, ClinicalTrials.gov, and World Health Organization International Clinical Trials Platform Search Portal and included RCTs for patients aged ≥15 years with SE on December 31, 2023. We compared multiple second-line AEDs for SE including fosphenytoin (fPHT), lacosamide (LCM), levetiracetam (LEV), phenytoin (PHT), phenobarbital (PHB), and valproate (VPA). The primary and secondly outcomes were termination of seizures integrating the absence of seizure recurrence at 30 min and 60 min, and adverse events associated with AEDs, respectively, with expressing as relative risk (RR) with a 95% confidence interval (CI). We conducted a NMA using frequentist-based approach with multivariate random effects, and assessed the certainty based on the Grading of Recommendations, Assessment, Development, and Evaluations framework.
RESULTS: Seven RCTs (n = 780) were included, and statistically significant difference was detected between VPA vs. PHB (RR, 0.67; 95% CI, 0.53-0.85; very low certainty), fPHT vs. PHB (RR, 0.66; 95% CI, 0.48-0.90; very low certainty), LCM vs. PHB (RR, 0.62; 95% CI, 0.41-0.93; very low certainty), and LEV vs. PHB (RR, 0.69; 95% CI, 0.51-0.94; very low certainty). Moreover, PHB was the highest in the ranking for termination of seizures. For adverse events, no significant reduction was observed owing to the selection of AEDs, although the ranking of PHB was the lowest.
CONCLUSIONS: PHB may have been the most effective for seizure termination as second-line AEDs in adult patients with SE. However, the certainty of almost all comparisons was \"very low\", and careful interpretation is essential.

Traumatic brain injury (TBI) and the subsequent Post-traumatic seizure (PTS) is a growing public health concern. Generally, anti-seizure drugs (ASDs) are recommended for PTS prophylaxis and treatment. This meta-analysis aimed to review the current state of knowledge and the evidence for the efficacy and safety of Levetiracetam (LEV) on the incidence of seizure in TBI patients compared to Phenytoin (PHT).
A search was carried out based on PubMed, MEDLINE, Europe PMC database, and Cochrane Library up to November 2023. A total of 16 studies (3 randomized clinical trials, 10 retrospective cohort studies, and 3 prospective cohort studies) including 5821 TBI patients included in our meta-analysis. We included studies comparing LEV and PHT after brain injury in both adults and children. Risk of bias assessment was done for randomized controlled trials (RCTs) with a risk-of-bias tool (RoB-2) and the Newcastle-Ottawa Scale (NOS) was used to assess the quality of cohort studies. Two RCTs in our meta-analysis had a high risk of bias, therefore we applied sensitivity analysis to evaluate the robustness of our results.
The most commonly reported dosage for LEV was 500 mg twice daily and for PHT it was 5 mg/kg. There was no significant difference between LEV and PHT groups in reducing the early seizure incidence (OR = 0.85; 95% CI = [0.60, 1.21]; p = 0.375, fixed-effect, I2 = 21.75%). The result of sensitivity analysis for late seizure showed no significant difference between LEV and PHT in reducing the late seizure occurrence after TBI (OR = 0.87; 95% CI = [0.21, 3.67]; p = 0.853, fixed-effect, I2 = 0%). The mortality in TBI patients treated with LEV was not statistically significant compared to the PHT group (OR = 1.11; 95% CI = [0.92, 1.34], p = 0.266). The length of stay in the hospital was not significantly different between the LEV and PHT groups (MD = -1.33; 95% CI = [-4.55, 1.90]; p = 0.421). However, in comparison to PHT, LEV shortened the length of ICU stay (MD = -2.25; 95% CI = [-3.58, -0.91]; p =0.001). In terms of adverse effects, more patients in the PHT group have experienced adverse events compared to LEV but the difference was not significant (OR = 0.69; 95% CI = [0.44, 1.08]; p = 0. 11).
The results of our meta-analysis showed LEV and PHT have similar effects on the occurrence of early and late seizures in TBI patients. Therefore, none of the drugs is superior to the other in reducing PTS. However, treating TBI patients with LEV did not shorten the length of hospital stay in comparison to PHT but reduced the length of ICU stay significantly. The analysis showed that patients in the LEV experienced fewer side effects than in the PHT group, while it was not sufficiently clear whether all reported side effects were related to the drug alone or other factors. The mortality was similar between the LEV and PHT groups. Finally, we recommend more high-quality randomized controlled trials to confirm the current findings before making any recommendations in practice.

BACKGROUND: Although phenytoin\'s potential benefits in wound healing, pain relief, and infection control across various wound types have been previously reported, its use in wound care remains limited.
OBJECTIVE: To conduct a comprehensive review to assess the efficacy of topical phenytoin compared with standard and alternative treatments for different wound types.
METHODS: The authors last searched Cochrane Library, PubMed, PubMed Central, and MEDLINE in June 2023. All English-language human RCTs and NRCTs from any time were included. The RoB 2 was used to assess quality of randomized trials, and the ROBINS-I was used to assess the quality of nonrandomized trials. Studies with a low risk of bias or some concerns in no more than 1 domain were included. Data collected and analyzed included wound type, interventions, sample size, outcome measures, and adverse effects.
RESULTS: The search yielded 101 studies, of which 17 RCTs and 8 NRCTs were eligible for inclusion. Of the included studies, 56% had a low risk of bias in all domains. The sample sizes varied between 20 and 130 (median, 60), with a total sample size of 1653 patients. Phenytoin improved wound healing in 17 of the 24 studies that evaluated it (71%), increased granulation tissue in 9 of the 10 studies that evaluated it (90%), provided analgesic effects in 7 of the 13 studies that evaluated it (54%), and inhibited bacterial contaminants in 6 of the 8 studies that evaluated it (75%). Adverse effects were rare (29%), minimal, and transient.
CONCLUSIONS: Phenytoin enhances wound healing and offers analgesic and antibacterial properties with minimal adverse effects. Further research is needed on optimal dosage of phenytoin, as well as frequency, delivery vehicles, and effects on other postoperative wounds.
BACKGROUND: Although phenytoin\'s potential benefits in wound healing, pain relief, and infection control across various wound types have been previously reported, its use in wound care remains limited.
OBJECTIVE: To conduct a comprehensive review to assess the efficacy of topical phenytoin compared with standard and alternative treatments for different wound types.
METHODS: The authors last searched Cochrane Library, PubMed, PubMed Central, and MEDLINE in June 2023. All English-language human RCTs and NRCTs from any time were included. The RoB 2 was used to assess quality of randomized trials, and the ROBINS-I was used to assess the quality of nonrandomized trials. Studies with a low risk of bias or some concerns in no more than 1 domain were included. Data collected and analyzed included wound type, interventions, sample size, outcome measures, and adverse effects.
RESULTS: The search yielded 101 studies, of which 17 RCTs and 8 NRCTs were eligible for inclusion. Of the included studies, 56% had a low risk of bias in all domains. The sample sizes varied between 20 and 130 (median, 60), with a total sample size of 1653 patients. Phenytoin improved wound healing in 17 of the 24 studies that evaluated it (71%), increased granulation tissue in 9 of the 10 studies that evaluated it (90%), provided analgesic effects in 7 of the 13 studies that evaluated it (54%), and inhibited bacterial contaminants in 6 of the 8 studies that evaluated it (75%). Adverse effects were rare (29%), minimal, and transient.
CONCLUSIONS: Phenytoin enhances wound healing and offers analgesic and antibacterial properties with minimal adverse effects. Further research is needed on optimal dosage of phenytoin, as well as frequency, delivery vehicles, and effects on other postoperative wounds.

OBJECTIVE: Antiseizure medications (ASMs) are commonly categorized as enzyme-inducers and non-enzyme-inducers based on their propensity to enhance the metabolism of concomitantly administered drugs. This systematic review and network meta-analysis aimed to rank ASMs as cytochrome P450 3A (CYP3A)-inducers based on a comparative assessment of ASM-induced reduction in the concentrations of sensitive substrate drugs.
METHODS: The protocol was registered with PROSPERO (International Prospective Register of Systematic Reviews; CRD42022335846), and the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) standards were followed. We searched MEDLINE, Embase, and Cochrane until March 14, 2023 without an initial date restriction. Data were additionally obtained via the US Food and Drug Administration database. Studies had to be prospective, with ASM monotherapy for ≥5 days. The primary parameter was the magnitude of change in the area under the concentration-time curve of CYP3A substrates following treatment with the ASM. The standardized mean difference (SMD) was used as the point estimate for the indirect comparisons between ASMs using the pairwise method. Bias risk was assessed using the PKclin tool.
RESULTS: We identified 14 open-label, fixed-sequence studies with 370 participants. The effect size of 600 mg/day carbamazepine did not differ from those of 300 mg/day phenytoin (SMD = -.06, 95% confidence interval [CI] = -.18 to .07) and 200 mg/day cenobamate (SMD = -.11, 95% CI = -.26 to .04). Carbamazepine at 600 mg/day was the strongest CYP3A-inducer (P-score = .88), followed by carbamazepine 400 mg/day (.83), phenytoin 300 mg/day (.79), and cenobamate 200 mg/day (.73). Eslicarbazepine (800 mg/day) ranked higher than cenobamate 100 mg/day and oxcarbazepine 900 mg/day (.60, .39, and .37, respectively).
CONCLUSIONS: Despite the limited number of studies, our network meta-analysis emphasizes that the magnitude of ASM effects on CYP3A substrate metabolism is a dose-dependent continuum. When possible, ASM classification as inducers should apply cutoff values tailored to the outcome. Prescribers should monitor plasma concentrations or clinical effects of CYP3A substrates and consider selecting concomitant medications accordingly.

This retrospective chart review examined dose reductions and discontinuations of concomitant antiseizure medications (ASMs) following cenobamate initiation and maintenance in patients with epilepsy treated at MetroHealth (Cleveland, OH) between 9/1/2020-9/26/2022. Concomitant ASM dose adjustments and treatment-emergent adverse events (TEAEs) were assessed. Efficacy (100 % seizure reduction) was examined among patients who received cenobamate for ≥ 3 months at data cutoff (including titration). As of 9/26/2022, 95 patients received cenobamate (mean age, 45.9 years; 48.4 % female, median exposure 7.5 months). Five patients (5.3 %) discontinued (n = 1 withdrawal by patient; n = 1 noncompliance; n = 3 adverse event). Among the 90 patients taking cenobamate at data cutoff, 50 % (45/90) discontinued ≥ 1 concomitant ASM, most commonly clobazam (n = 18), levetiracetam (n = 10), and phenytoin (n = 7); 21 patients (23.3 %) had additional concomitant ASM dose reductions, most commonly phenytoin (n = 6) and clobazam (n = 4). Sixteen patients received cenobamate monotherapy. Among 79 patients who received cenobamate for ≥ 3 months at data cutoff, 51.9 % (41/79) were seizure-free for ≥ 3 months. Of the 41 seizure-free patients, 58.5 % (24/41) were taking 100 mg/day of cenobamate. Sixteen of the 95 cenobamate-treated patients (16.8 %) reported 22 TEAEs. The most common TEAE was fatigue (n = 7). These data suggest that cenobamate therapy may allow reduction or elimination of polytherapy in some patients.

Physiologic changes due to aging, pregnancy, nutritional status, drug interactions, and can affect pharmacokinetics and pharmacodynamics of antiepileptic drugs. In this review article, the interactions between phenytoin and herbs recorded in the literature were summarized according to the Medline database (via PubMed). Our results revealed that, changes in phenytoin\'s bioavailability were reported for co-administration of herbs or herbal extracts. An increase in phenytoin blood levels was established with Piper nigrum, Mentat, and Lipidum sativum in in vitro and/or in vivo studies. In contrast, herbphenytoin interactions led to sub-therapeutic levels of phenytoin in other cases with herbs such as Cannabis, Ginkgo biloba, Morinda citrifolia, Nigella sativa, and Trigonella foenum graceum. In addition, the findings of other pharmcodynamic experiments showed that various herbs, including Zizyphus jujube, Terminalia chebula, Curcuma longa L, and Centella asiatica, improved the pharmacological impact of phenytoin. To reduce the patients\' health risks, health professionals involved in their treatment are expected to be thoroughly educated about the interactions between phenytoin and medicinal plants.

We aim to assess the effect of anti-epileptic drug (AED) prophylaxis for early or late posttraumatic seizures, targeting the pediatric population with traumatic brain injury (TBI). We systematically searched for studies reporting the incidence of posttraumatic seizures in pediatric patients who suffered from TBI and received AEDs prophylactically following their TBI incident. Studies that included adult patients, adult and pediatric patients but did not report results for the pediatric population separately, and patients who did not suffer from a TBI were excluded. Studies that did not indicate the use of antiepileptic drugs prophylactically following TBI were excluded. A total of 10 studies were included involving 4621 posttraumatic brain injury patients of the pediatric age population (<18). Five studies assessed the effect of prophylaxis on early seizures, four on late seizures and one on any seizure. The mean incidence of posttraumatic seizures with AED prophylaxis was 8% for early seizures and 7.1% for late seizures. Moreover, one study revealed no benefit of AED prophylaxis for early posttraumatic seizures. Meta-analysis revealed a significant difference in the incidence of early posttraumatic seizures with antiepileptic prophylaxis. However, no significant difference for late posttraumatic seizures has been shown. In conclusion, AED prophylaxis seems to be effective against early posttraumatic seizures for the pediatric population, with levetiracetam possibly being more effective. Also, there is no observed benefit for late posttraumatic seizures.

Phenytoin (PHT) was first synthesized as a barbiturate derivative and was approved in 1953 by the Food and Drug Administration. This work aimed to review the pathophysiology, epidemiology, clinical presentation, and treatment of PHT-associated movement disorders (MDs). Studies were searched in relevant databases (ScienceDirect, Google Scholar, Excerpta Medica, Latin American and Caribbean Health Sciences Literature, Medline, and Scientific Electronic Library Online) and were selected by two reviewers irrespective of language between 1963 and 2021. Papers of PHT-induced ataxia alone or tremor were excluded. In total, 127 reports with 219 individuals who developed MDs associated with PHT were encountered. MDs found: 126 dyskinesias, 49 myoclonus, 19 dystonia, 14 parkinsonism, 6 tics, 3 stuttering, and 2 restless legs syndrome. The mean age was 35 years (standard deviation [SD]: 23.5) and the predominant sex was male (53.4%). The mean PHT dose when the MD took place was 370.4 mg (SD: 117.5). A serum PHT concentration was reported in 103 cases, ranging from 4 to 110 μg/mL (median: 27.7 μg/mL). No significant relationship was found between PHT dose and age or PHT level. The mean onset time of PHT-associated MD was 23.4 months (SD: 4.4). The mean recovery time after MD management was 3.7 weeks (SD: 1.1). Regarding management, the most common form was PHT withdrawal in 90.4%. 86.3% of the individuals recovered fully. PHT-induced MD was extensively reported in the literature. Only general terms were used in the majority of the reports. The mechanisms underlying the adverse events caused by PHT probably depend on the presence of predisposing factors.

Drug-induced cutaneous pseudolymphoma (CPL) is a common form of pseudolymphoma and there are numerous drugs associated with it. In this study, we performed a systematic review of the literature by searching PubMed/Medline and Embase databases to determine the most common drugs responsible for CPL and to define the demographic, clinical, histopathological and immunopathological characteristics of patients (updated on 30 December 2020). From 883 initially found articles, 56 studies (89 reported cases) were included. The mean age of patients was 54.4 ± 17.7 (ranging 8-86) years, and 46 (51.7%) were men. The median time interval between drug intake and CPL occurrence was 120 days (range 1-7300 days). The shortest median time interval between taking the drug and the onset of the disease was observed among patients taking antidepressants (60 days) (range 7-540) and the longest median time interval was observed in individuals using immunomodulators (300 days) (range 3-7300). The most-reported drug categories causing CPL were anti-hypertensives (17.9%), anticonvulsants (14.6%), monoclonal antibodies (13.4%) and antidepressants (11.2%). Moreover, the most common drugs were phenytoin (6.7%), amlodipine (5.6%), fluoxetine (5.6%) and carbamazepine (4.4%). Histopathological evaluation of 76 cases revealed 62 (81.5%) reports of T-cell infiltrations. Furthermore, positive reports of CD4 (94.0%), CD8 (93.0%) and CD30 (87.5%) were noted. The lowest prevalence of CD30-positive reports was observed among monoclonal antibodies. In conclusion, anti-hypertensives, anti-convulsants, monoclonal antibodies and anti-depressants are the most common drugs responsible for CPL. It mostly presents in middle-aged patients with almost no gender difference as pruritic papules, nodules and plaques.